Introduction: The treatment of osteoarthritis (OA) of the proximal interphalangeal joint (PIPJ) remains controversial. This study compared outcomes of arthrodesis versus prosthetic joint arthroplasty in the treatment of OA or post-traumatic arthritis of the index finger PIPJ, with the hypothesis that patients treated with arthrodesis will have improved functional outcomes compared to those treated with prosthetic arthroplasty.

Methods: A retrospective review was conducting analyzing outcomes of patients with primary OA or post-traumatic arthritis of the index finger PIPJ treated with arthrodesis or arthroplasty. Preoperative and postoperative assessments included digit range of motion (ROM), grip and pinch strength, a patient-rated pain score, and radiographic analysis.

Results: Seventy-five patients (81 arthritic index PIPJ) were followed for 39 months (SD=18) on average. Seventy-two patients had OA and 9 had post-traumatic arthritis. The average age was 60.0 years (SD=12.7). Thirteen patients were treated with PIPJ arthrodesis and 68 by arthroplasty. Patients treated by arthrodesis had an average PIPJ fusion angle of 31.6º (SD=10.8) of flexion and an average increase in grip strength of 2.2-kg (SD=7.6), increase in opposition pinch strength of 1.9-kg (SD=1.2) and increase in apposition pinch strength of 1.2-kg (SD=1.9) postoperatively. Those treated with arthroplasty had an average loss of PIPJ motion of 3.7º (SD=20.4) and an average increase in grip strength of 1.7-kg (SD=8.0), increase in opposition pinch strength of 1.4-kg (SD=0.7) and increase in apposition pinch strength of 0.6-kg (SD=2.7) postoperatively. The decrease in ROM was significantly greater for those receiving arthrodesis versus arthroplasty (p<0.05), but there were no differences in grip or pinch strength between groups. None of the patients treated with arthrodesis had persistent pain at last follow-up (n=0/13), compared to 8.8% of patients treated with arthroplasty (n=6/68), (p<0.05). Radiographic analysis revealed nonunion in 15.4% of the arthrodesis group (n=2/13), and osteolysis, subsidence, hyperextension or flexion of the implant in 27.9% of the arthroplasty group (n=19/68). Those treated with arthrodesis had both a 15.4% complication rate and revision rate (n=2/13) compared to those treated with arthroplasty, who had a 41.1% complication rate (n=28/68) and a 32.4% revision rate (n=22/68). The complication rate was significantly less in the arthrodesis group (p<0.05).

Conclusion: While PIPJ arthroplasty may offer increased ROM compared to arthrodesis, patients undergoing arthroplasty lost motion postoperatively. Young, active patients with OA or post-traumatic arthritis of the index finger have improved functional outcomes with PIPJ arthrodesis compared to arthroplasty, specifically with regards to pain and complications.